Apparatus for holding and removing a knitwork in a double cylinder circular knitting machine

ABSTRACT

A double cylinder knitting machine having means for applying a vacuum to the upper cylinder during knitting and air under pressure thereafter to remove the finished workpiece. A basket is arranged open at one end coaxially with the upper cylinder and closed at its other end. A plenum surrounds the basket and the vacuum and pressurized air is supplied through the plenum.

United States Patent, 1

Uhlir et a1.

11* 3, 41,112 [451 Oct. 15, 1974 Filed: June 1, 1972 Appl. No.: 258,897

Assignee:

Foreign Application Priority Data June 2, 1971 Czechoslovakia .1. 4036-71 Int. Cl D04b 15/88 Field of Search 66/149 S, 1 4, 149 R, 150,

US. Cl 66/14, 66/149 S [56] References Cited UNITED STATES PATENTS 3,063,275 11/1962 Luchi 66/149 S 3,108,462 10/1963 Tenconi 66/149 5 3,159,015 12/1964 Moretla 66/153 3,392,551 7/1968 Tenconi 66/152 3,473,350 10/1969 Scheel 66/149 S 3,550,403 12/1970 Shields 66/150 3,564,875 2/1971 Foreman 66/149 3,745,794 7/1973 Brackett 66/149 S FOREIGN PATENTS OR APPLICATIONS 1,411,420 '1965 France 66/149 S 1965 France 66/149 S Primary Examiner-W. C. Reynolds Assistant ExaminerAndrew M. Falik l Attorney, Agent, or Firm--Murray Schaffer [5 7] ABSTRACT A double cylinder knitting machine having means for applying a vacuum to the upper cylinder during knitting and air under pressure thereafter to remove the finished workpiece. A basket is arranged open at one end Icoaxially with the upper cylinder and closed at its other end. A plenum surrounds the basket and the vacuum and pressurized air is supplied through the plenum.

: 6 Claims, 4 Drawing Figures BACKGROUND OF INVENTION The present invention relates to double cylinder circular knitting machines and in particular to such a machine provided with means for pneumatically holding the knit work during processing and for releasing the same after completion.

Circulari knitting machines for the manufacture of ladies stockings, tights and similar stockings, which are separately finished with toes, and the non-separated type having connecting draw courses, have been provided with means for conveying the knit work through the use of pressurized air. Such devices comprise a rotating housing located at the axial end of the needle cylinder to which a conduit is connected leading to a collecting vessel. The opposite axial end of the needle cylinder is provided with a co'nduit'connected to a source of pressurized air. The knit work is blown by the air through the cylinder and out into the collecting vessel.

The above devices can only be used with success when applied to the lower cylinder, so that the movement of air and withdrawal of the knit goods can be enhanced by gravity. In machines, in which the knit work is advantageously formed and withdrawn through the upper needle cylinder, e.g. in the-manufacture of closed toe stockings, this arrangement has serious drawbacks. First, excessive pressure must be used and secondly, the height .of the machine must be enlarged in order to accommodate the long ladies stockings during the completion of the toe.

It is an object 'of the present invention to provide a double needle cylinder knitting machine overcoming the disadvantages and drawbacks of the prior art.

It is another object to provide an improved-knitting machine capable of forming long and extra long stock ings and the like, with closed toes.

It is still another object to provide a knitting machine having pneumatic conveyor means which is simple in construction and not excessively enlarged.

These objects, other objects and numerous advantages will be seen from the following disclosure.

SUMMARY OF INVENTION cylinder. The basket'is mounted for rotation about the axis of the machine andv is surroundedby 'ahousing whichv forms a plenum thereabout. A source of air underpressure and vacuum is provided'having means lower end of the lower cylinder which is closed bya hinged door during the vacuum portion of the cycle so that air isdrawn into the cylindersbetween the knockover space between the upper and lower cylinders.

The porous basket comprises a cylindrical vessel closed at one end. Preferably, the vessel may bev fixed to the upper cylinder for conjoint rotation, although it the following description and shown in the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS In the drawings: I FIG. 1 is a view of a double cylinder knitting machine, in section along its vertical central axis showing its drive means and the pneumatic means according to v the present invention, showing the withdrawal of the knit work, FIG. 2 is a viewsimilar to FIG. 1, showing the dis- 7 charge of the knit work,

for selectively circulating the air throughthebasket and the bore of the cylinders. The air under vacuum,

being directed to"withdraw the knit work upwardly above the knockover plane'durin'gthe knitting opera- FIG. 3 is a sectional view along line A-A of F IG. 1,

and

FIG. 4 is a sectional view along line A A of FIG. 2.

DESCRIPTION OFINVENTIONI Turning to FIG. 1 there will be seen a double cylinder knitting machine particularly adapted for the formation of hosiery-and the like. The lower and upper needle cylinders 1 and 2 are axially aligned and are provided with a plurality of longitudinal grooves 3 in each of which rides a needle 4 on which the knit work 5 is conventionally formed. The usual sinkers, jacks, cams, etc., are provided butoniitted from the drawing for the sake of clarity. The upper cylinder 2 is joumalled in a radial ball bearing 6, secured within a socket on the upper flange or rail'7 of the machine frame, while the lower needlecylinder l is similarly mounted on radial ball bearing 8v in the lower flange or rail 9 of the machine. The cylinders 1 and 2 are thus secured against axial movement but retained for rotation about their commonrcentral axis. The cylinders are axially spaced from each other to provide a space for movement of the yarn or thread and which, in general, lie along the .knockover plane of the'machine, generally defined by the horizontal arrow'P;

A gearwheel l2'is'fixedly secured about the upper cylinder], and held in conjoint rotation with it by akey a'nd keyway 10. The gear wheel 12 is held against axialv movementby a nut 11' pressing it againsta shoulder of the cylinder. The gear wheel =12 meshes with a driving.

gear 13 which is -secured, by a pin 14, to the" upper end of a vertical'shaft 15. The shaft 15 :is journalled in the upperrail 7 and lower rail 9 by radial bearings 16. The lower cylinder 1 is'provided with-a gear wheel 19, below the rail 9', which similarly to the upper gear wheel 12, is secured by a key and keyway'l7 and an axial nut 18. The gear wheel 19 meshes with a small drive wheel 20 secured by a 'pin 21 to the lower end of the vertical shaft 15. The vertical shaft 15 is connected by extending linkages, gear train or other conventional means to the machine drive and motor mechanism, whereby the shaft 15 can cause the upper and lower cylinders to rotate. The gear wheels 12 and 19 and 13 and 20 are of the same dimension, respectively, so that the cylinders rotate in unison.

- The cylinders l and 2 define a central bore or passage O in which the knit work is formed and through which it may pass. A tubular outlet pipe 22, conveniently held by a bracket 23 is secured below the lower cylinder 1 so that its upper end is received with the cylinder 1 and its lower end is spaced above the floor 23. The lower end of the pipe 22 is provided with a door 26, hinged to pivot about the pin 25. The door 26 is provided with spring means to bias the same in a normally closed position, located below the door 26, is a collecting vessel 27, into which the knit goods are deposited.

Located above the cylinder 2 is a basket 28 having an opening coaxial with the bore 0. The basket 28 is, preferably, although not necessarily as will be seen, secured at its lip within the upper end of the upper cylinder 2. The basket may be in this embodiment welded force fit or secured by screws or rivets to the cylinder 2 so as to be conjointly rotatable with it and so as to form an enclosure above its upper end. The basket 28 is formed with a plurality of holes 29, in its side and top walls. It may be made of wire mesh, or expanded metal etc., so long as it is highly porous to moving air, but sufficiently enclosed to retain the knit work. An annular ring 30 is integrally secured to the baskets circumference adjacent its lower end, to which a ring, a vertical flap or wall member 31, having an arcuate section is fixed. Mounted on a vertical post 32 fixed to the upper rail 7 is a plenum 33 or L shaped cross-section. The plenum has an enlarged cylindrical portion 33a which surrounds the basket-28 and flap 31 to form a chamber thereabout, and'a circular tube conduit 33b extending in a horizontal direction outwardly therefrom. The plenum 33 sealing engages the outer wall of the upper end of the upper cylinder 2 and is provided with a low friction air sealing ring 34, or other suitablemeans to permit the cylinder to rotate relative to the plenum but maintain an air tight arrangement. The opening of the horizontal conduit 33b is relatively small with respect to the entire plenum, and is adapted to be occluded by the flap 31 which is proportioned, at least, to bridge the opening. The flap 31 may be larger than the opening but should preferably, besmall enough so that the opening is occluded for only a fraction of each cylinder rotation. As seen, a flap of only approximately a quarter of the circumference of the basket 28 is suitable.

Connected to the end of the conduit 33b isan elongated bore 34' whichleads'to a four way rotary valve 35 having a gate 37 pivotally mounted about a pin 36.

The four way valve leads through a conduit 38 to the suction side and through a conduit 39 tothe pressure side of a suitable air distributor 40, such as a turbine, pump or compressondriven viaa drive belt 41 by a motor 42. The valve is also open to atmosphere. The position of the-gate 37 is controlled by an suitable combination of solenoid, gears,-cams or linkages to the control drum or other central control means of the knitting machine, to act in synchronism with the knitting cycle.

In operation, the knit work 5 is produced in the usual manner by operation of the cylinders, needles, jacks etc. The gate 37 of the valve 35 is maintained in the position seen in FIG. 1 so that suction is applied through the plenum 33. The vacuum draws the knit work 5 upwardly through the bore toward the basket 28, simultaneously drawing air into the bore of the upper cylinder 2 through the space defining the knockover planeP, flowing in the direction of the arrows A through the air distributor 40 into the atmosphere. The door 26 is maintained closed by its resilient spring and the suction within the system. During the knitting operation the knit work 5 is continuously drawn upwardly into the basket, in a direction opposite to that of the knockingoff from the needles. During and after completion the knit work is sucked into the basket 28. Simultaneously and conjointly with the rotation of the upper cylinder 2, the basket 28 and the attached flap 31' are caused to rotate, causing the flap 31 to periodically pass in front of the opening of the conduit 33b into the plenum chamber 33a (see FIGS. 3 and 4). The passing flap 31 periodically occludes the opening, breaking the flow of air through the system, creating, as a consequence, a pulsing flow of air. This periodic opening and closing of the air flow creates a vibratory effect which acts on the knit work 5 to prevent it, or the loose thread, or yarn ends, from becoming caught or hooked into the openings 29 or itself occlude the opening into conduit 33b. This maintains the knit work in a free floating condition and also prevents a permanent interruption of air flow.

In a following phase, i.e., immediately after the completion and cutting loose of the knit work, the machine control causes the gate 37 to reverse into the position shown 'in FIG. 2, wherein the air flow is also reversed as is indicated by arrows B. The reverse flow causes air under pressure to be forced through the plenum chamber 33a through the bore 0 outwardly through the pipe 22 opening the door 26 at its end. The knit work .5 is consequently blown downwards, along the same path out of the pipe 22 into the vessel 27. The knitting operation can be cyclically repeated in rapid succession.

Various modifications can be made without departing from the spirit of the present invention. For example, the air distributor need not be connected to the upper cylinder but may be connected via the lower cylinder or even the pipe 22. Minor modifications may be required to control air flow in the desired direction but such modifications will be obvious. Also the basket 28 may not be secured to the upper cylinder, but may be joumalled independently and caused to rotate independently, within or out of synchronism with the cylinder by known bearing and transmission arrangements. Similarly, the flap'31 may be suspended from the top of the basket 28 or may also be independently mounted and driven by variable means to modify the length of the pulse.

The present disclosure is illustrative only and should not be taken as being limiting of the scope of the invention.

What is claimed:

1. A circular knitting machine comprising an upper and lower needle cylinder aligned along a common axis and spaced from each other to form a knock-over plane therebetween, said cylinders defining a central bore in which a knit work is formed during the knitting operation, a porous basket comprising a cylindrical vessel having an opening coaxial with said bore at one end and closed at its other end, said vessel being secured at its open end to the upper end of said upper cylinder for I to creating a pulsing flow of air and vacuum.

3. The circular knitting machine according to claim 1 including conduit means connecting said plenum to said source of air under pressure and vacuum and means for directing the flow of air or vacuum through said conduit.

4. The circular knitting machine according to claim 1 including a discharge pipe connected to the lower end of said lower cylinder, said pipe having a closure door, normally closed on the withdrawal of said knit work into said basket, to confine air flow into said upper cylinder through said space between the cylinders defining the knock-over plane, said door being openable on removal of said knit work to permit flow of air from said upper cylinder through the lower cylinder.

' 5. The circular knitting machine according to claim 3 including a flap member rotatable within said plenum to periodically occlude said conduit to create a pulsating air and vacuum flow.

6. The circular knitting machine according to claim 5 wherein said flap member is mounted on said basket for conjoint rotation. 

1. A circular knitting machine comprising an upper and lower needle cylinder aligned along a common axis and spaced from each other to form a knock-over plane therebetween, said cylinders defining a central bore in which a knit work is formed during the knitting operation, a porous basket comprising a cylindrical vessel having an opening coaxial with said bore at one end and closed at its other end, said vessel being secured at its open end to the upper end of said upper cylinder for conjoint rotation therewith, an air tight housing surrounding said basket forming a plenum thereabout, a source of air under pressure and vacuum and means for selectively circulating said air and vacuum through said bore, basket and plenum to withdraw said knit work upwardly above said knock-over plane into said basket during the knitting operation and to remove said knit work downwardly out of said lower cylinder upon completion of said knitting operation.
 2. A circular knitting machine according to claim 1, including means inserted within said circulating means to creating a pulsing flow of air and vacuum.
 3. The circular knitting machine according to claim 1 including conduit means connecting said plenum to said source of air under pressure and vacuum and means for directing The flow of air or vacuum through said conduit.
 4. The circular knitting machine according to claim 1 including a discharge pipe connected to the lower end of said lower cylinder, said pipe having a closure door, normally closed on the withdrawal of said knit work into said basket, to confine air flow into said upper cylinder through said space between the cylinders defining the knock-over plane, said door being openable on removal of said knit work to permit flow of air from said upper cylinder through the lower cylinder.
 5. The circular knitting machine according to claim 3 including a flap member rotatable within said plenum to periodically occlude said conduit to create a pulsating air and vacuum flow.
 6. The circular knitting machine according to claim 5 wherein said flap member is mounted on said basket for conjoint rotation. 